This study compared the outcomes of revision open carpal tunnel release following previous open versus endoscopic release to determine whether revision surgery has different results based on the type of initial surgical treatment. Thirty revision carpal tunnel releases were performed in 13 wrists that had previous endoscopic release and in 17 wrists with prior open release. At a follow-up visit an average of 30 months after surgery, self-assessment questionnaires demonstrated improved or complete symptom relief in 77% of the postendoscopic release group versus 47% in the previous open release group. Combining both groups, 18% of workers' compensation patients improved after revision surgery compared with 84% of those with conventional insurance (p < .05). Patients having persistent or recurrent symptoms following a previous endoscopic carpal tunnel release have a greater chance of symptom improvement or resolution compared with patients who had previous open carpal tunnel surgery. Our results support the observation that a higher incidence of incomplete release of the carpal tunnel is found with endoscopic surgery than with open release.